Piltdown Man

The Piltdown Man, one of the biggest scientific frauds of the 20th century, demonstrates that everyone, even so-called experts, can be gullible. [Page 759]On December 18, 1912, Charles Dawson presented hominid bone fragments he had discovered in a gravel yard near Piltdown, East Sussex, England, to the Geological Society of London. Dawson and his partner, Arthur Smith Woodward, keeper of the geological department at the British Museum, maintained the reconstructed fragments (skull, jawbone, and teeth) indicated the Piltdown Man was most likely the missing link between apes and humans. Thus began a notorious hoax that lasted for over 40 years. Why did most scientists of the day blindly accept the fraudulent findings when more scientifically credible missing links were ignored? Who perpetrated this blatant fraud? How was the scientific community deceived for so long?

Although some (mostly American and European) scientists soon questioned Dawson's findings, they were ignored or vigorously attacked. Why? British national pride definitely played a role. How could anyone question evidence that proved what every British citizen knew in his heart: of course Britain was the origin of modern man and civilization. Moreover, scientists had a working assumption that the missing link would have evolved mentally first, thus having a human-like brain with other features remaining ape-like.

When Dawson presented bone fragments suggesting a human-like skull and an ape-like jaw, many scientists were overjoyed that their hypothesis was correct (a clear example of confirmation bias—the tendency to favor information confirming existing beliefs.) Scientists who questioned the authenticity of the Piltdown Man discoveries were silenced two years later, when Dawson conveniently found new Piltdown Man fragments just two miles away from the original site. It would be too much of a coincidence to find this combination of fragments together twice; they must belong together.

Why did it take over 40 years (and over 500 scientific essays on Piltdown Man) for someone to look for evidence of fraud? Dawson was well known in the field. Though he was an amateur archaeologist, he made many significant finds, including a previously unknown species of mammal, three new dinosaur species, and a new form of fossil plant, and several of his discoveries were named after him (Plagiaulax dawsoni, Iguanodon dawsoni, and Salaginella dawsoni). For these finds, the British Museum named him an honorary collector, and he was elected a fellow of both the Geological Society of London and the Society of Antiquaries of London. Because Dawson was perceived as distinguished and reputable, he seemed a credible expert source whose findings must be correct.

It's interesting to note that in 1891, a Dutch paleoanthropologist and geologist found authentic remains in Java of an ape-man with a small brain that stood erect (Homo erectus.) Even though his facts were meticulously logged and documented, and he carefully verified his results, the scientific community ignored and ridiculed him. He had the misfortune to be an unknown, unconnected foreigner (of suspect credibility) who discovered something contradicting prevailing theories. (Yet another sad example of confirmation bias.)

Even in 1949, when a new flourine dating test revealed the age of the Piltdown artifacts as relatively recent rather than ancient fossils, it still didn't occur to anyone that something associated with Dawson could be a fabrication. Not until 1953, when Piltdown Man did not match with accumulating missing-link fossils discovered over the years, did someone examine the artifacts for deliberate fraud. J. S. Wiener was amazed at the strikingly clear indicators of fraud: There was obvious evidence that the teeth had been filed down. Later tests indicated that skull fragments were from medieval humans, the jawbone was from an orangutan, and the canine tooth was from a chimpanzee fossil. Bones were treated with an iron and acid solution, making them appear ancient, and the canine tooth was painted and patched with chewing gum.

...